My comment for years has been that most folk overestimate their average power needs and underestimate their peak power needs. Often by an order of magnitude or more either way.
Most music has much higher energy levels in the low frequenches. It will look like a right oriented downward slope on a spectrum analyzer. So less power is needed for the tweeters in a biamped system.No, not true. A loudspeaker with a flat frequency response and a flat impedance has the same efficiency for all frequencies.
Ok, no loudspeaker has a flat frequency response and/or a flat impedance. But, that does not explain your "when you go higher up the frequencies the required power lowers (with the same SPL)".
I think that I know where your thought comes from:
With a lot of music, the power is spread (roughly) equally accros all frequencies like pink noise. Meaning that there is the same amount of power in the range between 20 Hz - 200 Hz and 200 Hz - 2 kHz and 2 kHz - 20 kHz. If a 2-way loudspeaker has the crossover frequency around 3 kHz, then more than 2/3 of the power goes to the woofer and less than 1/3 of the power goes to the tweeter.
Was this it?
I think it is related to the size of the listening room.I’m still skeptical of mania for high power. I must listening at lower levels than most folks. On a dB meter, at loudest I ever listen to it might peak at 90. Usually averages about 80 with what I think is comfortable.
I don't think this is strictly correct. Pros who set up active crossovers for speakers generally will state that if all speaker elements have the same efficiency, than average power required tend to drop as the frequency rises i.e. 20-80hz@200watts, 80-300Hz@100 watts 300-3000@50watts 3000-20Khz@10 to 20 watts for a four way system. That is about a 3db drop in amp power per frequency segment from bass to treble, and some place the requirement lower at as much 5-6db per frequency segment. Again, that is presuming the same efficiency per driver.No, not true. A loudspeaker with a flat frequency response and a flat impedance has the same efficiency for all frequencies.
Ok, no loudspeaker has a flat frequency response and/or a flat impedance. But, that does not explain your "when you go higher up the frequencies the required power lowers (with the same SPL)".
I think that I know where your thought comes from:
With a lot of music, the power is spread (roughly) equally accros all frequencies like pink noise. Meaning that there is the same amount of power in the range between 20 Hz - 200 Hz and 200 Hz - 2 kHz and 2 kHz - 20 kHz. If a 2-way loudspeaker has the crossover frequency around 3 kHz, then more than 2/3 of the power goes to the woofer and less than 1/3 of the power goes to the tweeter.
Was this it?
I have in the past looked at the D-Sonic amps which I believe use Pascal modules.
It's a bit irksome when full bandwidth specifications are not available. All power levels quoted are at 1khz.
View attachment 59589
The peak output current is shown to be 30 amps on a single channel and 21 amps with Ch2/Ch3 with power varying from 2100 down to 400 watts at 1khz.
This seems odd where the Benchmark AHB2 has 29 amps peak with power from 100 to 180 watts into 4 ohms. Bridged, it is 380 watts into 4 Ohms. All Benchmark specifications are 20 Hz to 20 kHz.
I suspect power requirements are over inflated as are some power specifications.
- Rich
I am digging up this old thread, because I didn't want to open a new one and my question seems to be somewhat in line with the topic at hand:
When I try to determine how much amplifier power is required, I was curious whether REWs SPL measurements can be used.
During normal playback I measured an Lzpeak of around 88dB when I crank the volume of a bass heavy track.
Measured at the listening position, roughly 1m from the speakers, since it's a nearfield setup, 2 speakers playing.
Can that number be trusted? If I understand it correctly, SPL(z) weighted does not factor in human hearing and is a flat curve.
Seems awfully low, considering how loud it felt, suggesting that I am in the realm of 1W including transients.
Assuming REW is able to catch these... it sure is able to catch a slammed door, darn Neighbors messing up measurements. :<
Actually, what I am wondering is whether the transient SPL(Z) values are correct at 88dB. (Measured with a calibrated UMIK-1)So, you asked is it possible that what you considered to be loud was 88 dB. Yes, because 88 dB is loud.
Thank you for the explanation. One of these days I need to get me a new Multimeter *chuckles*
Actually, what I am wondering is whether the transient SPL(Z) values are correct at 88dB. (Measured with a calibrated UMIK-1)
The running SPL(C) value REW displays when I am listening to music fluctuates between 55dB and 65dB and goes into the low 70s when I push it.
At 440Hz, according to Senpai's measurements the Aria 906 have roughly 7Ω Impedance with a phase angle of +40°.
I don't think he measured the sensitivity but sound stage network did and came up with 87dB/W (Focal's datasheet gives an optimistic 89dB/W).
he Aria 906’s sensitivity measured 86.8dB/2.83V/m, which is typical for a speaker of this size and configuration. The impedance remains above 8 ohms from 700Hz to 20kHz, and dips to a low of 4 ohms at 200Hz, but never lower.
I am sorry but I do not understand the statement above. Both sentences seem to contradict each other.However, if you measure playing a 0 DBFS sine-wave, it represents the maximum volume.
It can not be measured steady-state.
I'm pretty sure that the correlation between SPL and pitchfork waving of my neighbor is also non linear.Bookshelf speakers so I don't think they are going to remain linear [...] above 100 dB.
To give extra headroom for low output sources (and quiet recordings) most amplifiers will be delivering maximum power with the rated input with the volume control at 1 to 2 o'clock. Maximum rotation of the volume control will be well into clipping with, say, a standard CD player as input.
Some of the more recent amps have a dB scale on the volume showing how close to maximum power you are selecting.
I am familiar with the Devialet models. On the "Expert" amps 0dB on the volume control is full power with rated input (like a digital input) but +15dB is available if a low output analogue input, like a FM tuner, is being used. The maximum output power can also be set in the configuration file to be lower if wanted. The Phantom speakers produce maximum output from a digital signal at a "70" volume setting but go to "100" where there will be limiting to avoid damage.